Publilius Syrus (fl. 46–29 BC[1]), was a Latin writer of sententiae. He was a Syrian who was brought as a slave to Italy, but by his wit and talent he won the favour of his master, who freed and educated him. Publilius' name, due to early medieval palatalization of 'l' between two 'i's, is often presented by manuscripts (and some printed editions) in corrupt form as 'Publius'.

His mimes, in which he acted himself, had a great success in the provincial towns of Italy and at the games given by Caesar in 46 BC. Publilius was perhaps even more famous as an improviser, and received from Caesar himself the prize in a contest in which he vanquished all his competitors, including the celebrated Decimus Laberius.

All that remains of his corpus is a collection of Sententiae, a series of moral maxims in iambic and trochaicverse. This collection must have been made at a very early date, since it was known to Aulus Gellius in the 2nd century AD. Each maxim consists of a single verse, and the verses are arranged in alphabetical order according to their initial letters. In the course of time the collection was interpolated with sentences drawn from other writers, especially from apocryphal writings of Seneca the Younger; the number of genuine verses is about 700. They include many pithy sayings, such as the famous "iudex damnatur ubi nocens absolvitur" ("The judge is condemned when the guilty is acquitted") adopted as its motto by the Edinburgh Review.

As of 1911, the best texts of the Sentences were those of Eduard Wölfflin (1869), A. Spengel (1874), and Wilhelm Meyer (1880), with complete critical apparatus and index verborum; editions with notes by O. Friedrich (1880), R. A. H. Bickford-Smith (1895), with full bibliography; see also W. Meyer, Die Sammlungen der Spruchverse des Publilius Syrus (1877), an important work.

Seneca the Younger had strived to develop a "sententious style" like Publilius throughout his life time.[2] He also quotes Syrus in his Moral Epistles to Lucilius in the eighth moral letter, "On the Philosopher's Seclusion"[3] and the ninety-fourth, "On the Value of Advice".[4]